Digital BW, The Print

Hi,
it was interesting to hear Henry Wilhelm's comments about the first BW RC papers - the Titanium Dioxide oxidised the papers contained, released peroxides that attacked the silver.

Some inkjet papers are brightened with Tio2 - I've heard that PremierArt Matt BW is. 

I wonder if this release of peroxides has ramifications for our injet prints. I've found that the PremierArt holds its whiteness slightly better over a year on the wall, than other bright white papers I've tried, so hopefully it's ok.

Richard

--
www.richardsmallfield.com 

   A jury consists of twelve persons chosen to decide who has the 
   better lawyer."
   --Robert Frost

TiO2 is virtually inert.


On 11/9/08 6:15 PM, "Richard Smallfield" <r.smallfield@...>
wrote:

>  
>  
> 



[Non-text portions of this message have been removed]

Interesting - maybe he got the wrong molecule! He definitely said TiO2 in the podcast on the Luminous Landscape.

Richard

At 12:47 p.m. Monday 10/11/2008, you wrote:
>TiO2 is virtually inert.

--
www.richardsmallfield.com 

   "The gladiator is making his plan in the arena." (i.e. too late.)
   --Lucius Annaeus Seneca, the Younger 4 B.C. - A.D. 65

[Non-text portions of this message have been removed]

TiO2 has been the pigment used in virtually all white paints  for quite some
years.  The reason for its being the prime white pigment in the paint
industry is it¹s stability and lack of reactivity even when exposed to all
kinds of noxious environmental pollutants. Its lack of reactivity is also
why it is a safe pigment that provides no danger to the painter or for that
matter the owner of the property that has been painted. I have used  pounds
of it in making panels for my wife¹s egg tempera paintings. Some painters
prefer lead based whites due to their creamy consistency and flow on the
canvas but they can and do discolor over time and as with all lead based
pigments they are inherently dangerous and less than stable.

Roger


On 11/9/08 6:50 PM, "Richard Smallfield" <r.smallfield@...>
wrote:

>  
>  
> 
> Interesting - maybe he got the wrong molecule! He definitely said TiO2 in the
> podcast on the Luminous Landscape.
> 
> Richard
> 



[Non-text portions of this message have been removed]

Richard Smallfield wrote:
> Hi,
> it was interesting to hear Henry Wilhelm's comments about the first BW RC papers - the Titanium Dioxide oxidised the papers contained, released peroxides that attacked the silver.
> 
> Some inkjet papers are brightened with Tio2 - I've heard that PremierArt Matt BW is. 
> 
> I wonder if this release of peroxides has ramifications for our injet prints. I've found that the PremierArt holds its whiteness slightly better over a year on the wall, than other bright white papers I've tried, so hopefully it's ok.


About a year ago similar threads on TiO2, Barite, Aluminium, 
OBA's etc happened on this list.
Worth reading again I think.

-- 
Met vriendelijke groeten, Ernst


|  Dinkla Grafische Techniek  |
|     www.pigment-print.com    |
|             ( unvollendet )            |

Richard Smallfield wrote:
> Hi,
> yes I recall that thread - it was Wilhelm's comment that was interesting.
> 
> Richard

Wilhelm's comment should be seen in the context of the early
1970's when analogue RC paper was introduced.
The RC (Polyethylene) barrier directly behind the emulsion
layer hardened and cracked in a reaction with the rutile
TiO2 whitener that was mixed in., releasing more oxidants in
the process. The photochemical process is roughly UV light 
bombarding TiO2, releasing peroxides that harden and crack 
the polyethylene and allow peroxides to attack the image..

Meanwhile a lot has been changed in the polymers available
for the barrier and in the whiteners to add to that mix.
Antioxidants are added and UV light reaching TiO2 is
reduced. Related to that: OBAs filter UV light out as long
as they are active. In theory any oxidising agent would
attack colorants, dye more than pigment but a modern RC
layer no longer releases peroxides to that degree. With UV
light available it is more likely that the colorants will
bleach due to the UV than to the possibly released
peroxides. The Ozone tests done by  Image Engineering for
ColorFoto made it clear that colorants are better protected
to ozone in RC papers than on non-RC papers. Possibly
because the RC layer blocks ozone coming through the paper
base but more likely the anti-oxidants mixed in neutralise
the ozone. Carbon pigment particles used in B&W inks are
more or less inert to influences described here.

With the Vivera pigment and HP RC paper, two components of
aging are estimated to be around 70 years: ozone fading of
the pigments and the RC barrier falling apart. The
lightfading resistance is 80 - 105 years. HM's PhotoRag
however will show ozone fading of pigment between 50-60
years for the same ink in bare exposure, the lightfading
resistance is more than 115 years.  So for bare exposure the
RC paper may be a better choice than the Photorag. Maybe it
is bad taste to suggest plastic as a carrier of art, I know.
Cotton, fiber, baryte and gelatine suggest quality for much
longer .........

http://digitalkamera.image-engineering.de/downloads/Haltbarkeit_Papiere-Cofo.pdf
bottom of page

Wilhelm's ozone testing looks like being less severe than 
Image Engineering's test, Wilhelm labelled a lot of ozone 
tests in the past as being "still in test" while the recent 
tests (Harman Fibers, Photorag, Epson Exhibition) right now 
all show a >100 years label. For the Fiber papers I like to 
see an Image Engineering Ozone test to get some perspective 
of their ozone resistance.

Part of that was discussed in the old threads or at least
links to articles on that subject were there

-- 
Met vriendelijke groeten, Ernst


|  Dinkla Grafische Techniek  |
|     www.pigment-print.com    |
|             ( unvollendet )            |

I think the only way to exhibit ANYTHING 'bare bulb' is to laminate,
and that's a whole other area we have unclear data on and varies from
compapny to company. There are so many contaminants in the atmosphere
that we have an impossible time measuring them in the lab or even in
the real world to even know what is being filtered and at what time of
year with what humidity. Urban environments like Cairo, Athens, Mexico
City, Beijing, even LA, may show totally different results than less
densly populated and less polluted cities. But it is true from what
HAS been done, that rag papers are going to absorb pollutants at far
greater rates than plastic media, or media without a post print
coating layer.We all know about the reports of Hahnemuhle and Innova
rag papers being stained to yellow right in the box from bad packaging.

In a side note, I have an artist friend who created a series of very
large photomural mosaics 12 years ago that were printed with
traditional  chemical rc black and white Kodak RC papers, but
laminated with a good uv laminate before framing. They  hang in a
major airport just under giant skylights where they are slammed with
strong daylight from above, every day, far exceeding Wilhelms 450 lux,
on a weekely basis, season after season, year after year. To my
amazement none of them have either stained or faded in any perceivable
way. Since I photographed the piece when it was installed I am very
familiar with how they looked inititally. This is really surprising to
me. I expected them to last no more than a couple of years without
significant changes.  Wilhem's comments about the stability of rc
black and white silver media showed it at the bottom of his list of
usable media if you want it to last. The rapid fixing and washing is
far from ideal in automated chemical processors and they are full of
obas. 

The issue for most of us in producing a laminated installation for
public art projects, is finding a shop to do it well, or even decently
without bubbles, dirt, wrinkles, and the like. It's not easy. Joel
Meyerowitz is lucky he lives in Manhattan where such a place does
exist for artists. I haven't been lucky in that regard.

john